\documentclass{article}
\usepackage{amssymb,amsmath,amscd,concmath}
\pagestyle{empty}
\begin{document}
\begin{equation*}\textbf{M}_{k} = [\textbf{F}_{k}^{-1}]^{T} \hat{\textbf{Y}}_{k|k} \textbf{F}_{k}^{-1} \end{equation*}
\end{document}
